Entereg

EXTON & PHILADELPHIA, Pa., May 31, 2006 -- Adolor Corporation and GlaxoSmithKline announced today that the Food and Drug Administration (FDA) has accepted as complete, Adolor's response to the July 2005 New Drug Application (NDA) approvable letter for Entereg for the management of post-operative ileus (POI). The FDA informed Adolor that the response is considered a class 2 resubmission with a user fee goal date of November 9, 2006.

"We are pleased the Agency has accepted the complete response for review," stated James Barrett, Ph.D., senior vice president, chief scientific officer and president, research of Adolor Corporation. "The early achievement of this milestone takes us one step closer to achieving our goal of bringing this novel treatment to patients and surgeons. We look forward to working with the Agency throughout the review."

"We were delighted to announce positive results of Study 314 in February of this year, setting the stage for this complete response to the Agency," said Kevin Lokay, vice president of oncology and acute care at GlaxoSmithKline. "This is an important step toward our goal of bringing a new treatment option to physicians who treat POI and to patients who may benefit. We will be working closely with Adolor in the regulatory review process."

On July 21, 2005 the FDA issued an approvable letter for Entereg (alvimopan), an investigational drug under review for the management of postoperative ileus (POI) by acceleration of the time to recovery of gastrointestinal (GI) function following bowel resection surgery. The FDA indicated in the letter that before the NDA may be approved, it was necessary to provide additional proof of efficacy to support the proposed use of Entereg following bowel resection surgery. The FDA indicated that this may be achieved by demonstrating statistically significant results in at least one additional clinical study, and that this could potentially be addressed with the positive results from Adolor's Study 14CL314. The FDA also indicated that Adolor must provide justification that the median reduction in time to gastrointestinal recovery seen in bowel resection patients treated with Entereg is clinically meaningful.

About Postoperative Ileus (POI)

Many patients undergoing abdominal surgery experience transient gastrointestinal impairment. This condition, known as postoperative ileus, may be exacerbated and prolonged by multiple factors including the use of opioid analgesics for pain relief. POI is characterized by abdominal distension and pain, nausea and vomiting, reduced desire to eat, and an inability to pass gas or stool. POI is a major contributor to prolonged hospital stays. Consequently, POI represents a substantial burden on healthcare resources.

Despite the negative impact, there have been few advances in the treatment of POI since the introduction of nasogastric decompression over 100 years ago, which has limited effectiveness and is uncomfortable for patients. Currently, there are no drugs approved for the management of POI.

Entereg Collaboration

Adolor Corporation and GlaxoSmithKline are collaborating on the worldwide development and commercialization of Entereg for POI and the gastrointestinal side effects of opioids associated with extended use for persistent pain.